Improved dentist s vulcanizing flask



` @with tatrpetwt @Hirsi IMPROVED DENTISTS VULGANIZING FLASK.

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'IO ALL WHOM IT MAY CONCERN:

Be it known that I, HENRY F. CLARK, of Poughkeepsie, in the county of Dutchess, and State of New York, have invented a new andimproved Dentists Vulcanizing Flask; and I do hereby declare that the following is a full, clear, and exactdescription thereof, which will enable-others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part "of this specification. I

My invention relates to the manner in which fasten the parts ofthe tlask together; the ask being used for vulcanizing the rubber used in dental operations, and the invention consists in holding the lask'together by keys applied, as will be hereinafter described.

Figure l represents a top vie-w of the l'lask.

Figure 2 is a side -view; and

Figure 3 is a section through the line x rc of fig. 1, showing the fastening device.

Similar letters of reference indicate like parts.

A represents the bottom ofthe flask, the edges of which projectvt'rom the ask proper snfliciently far to allow studs to be permanently attached to it. These studs are marked B in the drawing. Ol' these there may be more or less; three are shown in the drawing. These studs extend up to the top ofthe flask. C Cl are the 'two parts of the ilnsk; C, (or the upper portiom) called by foundrymen the cope, is closed at the top, forming a tight dish-shaped vessel when the open side is up. There are pairs of ears attached to this part, between which pairs the studs B pass. On the lower portion of the tlask C', called the nowel, (which is open or consisting of only a rim,) there are also pairs ot' ears corresponding in position and shape with the ears on the upper part of the ila-sk. hese ears are marked a on the upper part and I. on the lower part of the flask. Across the top ot` the pairs of ears, on the upper portion, there are grooves which guide the keys, and corresponding with this groove there are shoulders formed in the studs by forming channels through them sntlieiently wide to admit the keys. 1] indicates the shoulders against which the keys press in holding the flask together; fis the key. The parts of the liask are nicely fitted together, there being guide pieces, besides the studs, to keep them in place. It has been usual to bind the parts of the flask together by screw-bolts; but the'screwthreads, it' of iron, soon corrode and wear out, in consequence of the sulphur contained in the rubber` and it` they are of brass they soon become insecure by constant use. This fastening is not liable to any such objections. The flask and the fastening may be made of any suitable metal, and the fastening will be durable and -much more convenient than when made with screws. Whensit is desired to use theflask for forming and vulcanizing the rubber the flask is placed in a press, where sufficient power can be applied; the bottomfresting on a flat surfacaand the power being applied to the round boss which is seen on the centre of the` top part C. This boss is marked y in the drawing. When the parts'of the tia-sk are sucieutly pressed together the keys are inserted, when the pressure is remoyed, and the parts of the flask will be rmly held together.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is'

A dentists vulcanizing flask constructed substantially as herein shown and described, and with the parte secured and held together by keys, substantially as set forth.

' HENRY F. CLARK.

Witnesses:

EDGAR VINCENT, ABM W. Imsn. 

